1. Field of the Invention
This invention relates to a mechanism for producing orbital motion in a member of the mechanism.
2. Description of the Prior Art
A variety of shakers are known to those of ordinary skill in the art. In general shakers can be divided into classes depending upon their functions and purposes. Some shakers are designed exclusively for reciprocating motion whereas others are designed exclusively for orbital motion. Reciprocating motion is the first choice for dissolving powders in liquids, for solvent extraction in which two immissible solvents have to be shaken together, or for accelerating chemical reactions. Orbital shaking is the first choice for cultures as it eliminates wetting of the cotton hole plug in the neck of the flask and the smooth swirling motion provides more reproducable results. Similarly, many are designed for shaking materials under ambient conditions or in incubators whereas others are adapted for use with a water bath. The following foreign organizations are known to make shakers for use under ambient conditions or in incubators: Braun (Germany), Cenco (Holland), Desaga (Germany), Gerhardt (Germany), Weidolth (Germany), and Infors (Switzerland). The following organizations make and/or sell the same types of shakers in the United States: Eberbach, Fischer, Labline, New Brunswick Scientific Company, Inc., and Spectroderm Instruments, Inc.
Lauda of Germany is known to manufacture a water bath shaker. The following organizations also sell water bath shakers in the United States: Blue M, Eberbach, Labline, New Brunswick Scientific Company, Inc., Precision, Warner-Chilcott, and American Optical.
Prior art shakers tend to be either reciprocating or orbital, but not both. In addition, they can be relatively expensive to purchase and can be expensive to run due to their power consumption requirements. The New Brunswick "Aquatherm" Model Water bath shaker can be converted from reciprocating to orbital shaking by removing three fasteners and replacing the driving unit. It is believed that none of the well known shakers can be used either as a water bath shaker or as a regular conventional shaker with a choice of reciprocating or orbital motions. It is in the context of the foregoing prior art that the present invention arose.